Collapsible keyboard

ABSTRACT

A collapsible keyboard that is collapsible between a deployed configuration in which the keyboard is generally planar and a collapsed configuration, the keyboard being foldable about three substantially parallel axes between the deployed and collapsed configurations, the keyboard having four rigid subframes for supporting keys, each subframe being pivotally connected at a folding axis to an adjacent subframe. The keyboard preferably has support frames supporting keys thereon. The keys are slidable and are connected by flexible connectors that span the axes. The keyboard can be locked in either the collapsed or deployed configuration and can be combined with a remote communication unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of International Application PCT/GB98/00841, withan international filing date of Mar. 20, 1998, which claims priorityfrom GB/9705881.2 and has a priority date of Mar. 21, 1997.

The present invention relates to a collapsible keyboard.

There have been various proposals for collapsible keyboards for use withcomputers and particularly for use with portable computers. One of themain constraints when attempting to reduce the size of a portablecomputer is the fact that the keyboard must be greater than a certainminimum size in order to be usable by a person. If a keyboard is toosmall, the keys become too small and cramped to be used effectively. Inseveral prior art proposals, including for example that shown in U.S.Pat. No. 3,940,758, the number pad of the keyboard is positioned on aseparate part of the keyboard which is attached to the main portion ofthe keyboard holding the alphabetic and other control keys so that thenumber pad can be folded over onto the main part of the keyboard whenthe keyboard is not in use, thereby to reduce the overall size of thekeyboard. However, in practice, this still does not reduce the overallsize of the keyboard very much. As the other components of portablecomputers, such as display screens and hard disk drives, becomeincreasingly smaller as the technology improves, there is an increasingneed to reduce the overall size of the keyboard. Furthermore, there arevarious computers available now or shortly which do away with a keyboardand use a pen input to a touch-sensitive screen or voice-activation forexample. However, users often find a keyboard convenient to use, but donot wish to carry a separate keyboard with them as keyboards haveconventionally been very bulky. There is therefore also a need for anindependent keyboard which can be used as an optional accessory to acomputer and which is conveniently stored when not in use. Such akeyboard could also be used with mobile telephones, electronicorganisers and potentially with interactive television systems, screentelephone units, and the like.

EP-A-0640489 discloses a foldable computer which has a keyboard whichcan be folded in half about a central axis transversely of the keyboardand which is attached to a separate portion containing the processorwhich is foldable about an axis arranged longitudinally of the keyboard.

U.S. Pat. No. 5,459,461 discloses an inflatable keyboard which can bedeflated and then rolled or folded for storage and inflated for use.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a collapsiblekeyboard, the keyboard being collapsible between a deployedconfiguration in which the keyboard is generally planar and a collapsedconfiguration, the keyboard being foldable about three substantiallyparallel axes between the deployed and collapsed configurations, thekeyboard having four rigid subframes for supporting keys, each subframebeing connected at a folding axis to an adjacent subframe.

Preferably, the keyboard is foldable in one direction about the middleaxis and in the opposite direction about the adjacent axes. Thus, thekeyboard may fold through a “W” shape so as to collapse in aconcertina-like fashion.

The keyboard may have keys at least some of which are slidable in theplane of the keyboard in a direction transverse of said axes. As thekeyboard is folded, the slidable keys, which in the deployedconfiguration may overlap a folding axis, can move away from saidfolding axis so as to facilitate or allow folding of the keyboard andalso to provide a straight edge with no keys overlapping the foldingaxes in the collapsed configuration.

At least some of the slidable keys may be connected to other keys byflexible means passing over an axis so as to cause said at least someslidable keys to slide as the keyboard is folded. The keyboard isconstructed such that at least some of the slidable keys are biasedtoward their deployed position when the keyboard is deployed.

The keyboard may further comprise a support structure for keys. Thesupport structure is preferably a matrix of cells, each cellaccommodating a respective key. In the collapsed configuration, thesupport structure preferably encases each depressed key. This protectsand hides the key mechanism, particularly at the edges of the foldingaxes in the collapsed configuration. Where some of the keys areslidable, corresponding portions of the support structure may beslidable with the slidable keys.

A lock may be provided for locking the keyboard in its deployedconfiguration. The lock may comprise locking elements that are biasedinto recesses in subframes of the keyboard. The lock may be releasableby operation of a button connected to the locking means.

A lock may also be provided for locking the keyboard in its collapsedconfiguration.

The keyboard may be combined with a remote control unit. This hasparticular application for use with a television type unit, for example.

While reference is made herein primarily to the keyboard being usefulfor a portable computer, it will be appreciated that the principles ofthe present invention can be applied to a keyboard for a desktopcomputer, a so-called “personal digital assistant” or “electronicorganiser”, or used as an independent portable pocket-sized keyboard foruse with such devices, or, indeed, to any kind of generally planar inputdevice such as a keyboard for a musical instrument such as an electricpiano or synthesizer.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way ofexample with reference to the accompanying drawings, in which:

FIGS. 1A to 1C are respectively a plan view, a side elevation and an endelevation of an example of a keyboard in its deployed configuration;

FIG. 2 is a schematic fragmentary plan view of the keyboard;

FIGS. 3A to 3C are respectively views of the keyboard just after foldinghas begun, almost in its collapsed configuration, and in its fullycollapsed configuration;

FIG. 4 is an exploded view of one section of the keyboard;

FIGS. 5A to 5C are sequential perspective views of a preferred assemblymethod for a portion of the keyboard;

FIG. 5D is a partial exploded view of an alternative embodiment of FIG.5A;

FIG. 6A is a partial schematic plan view of a preferred lockingmechanism for the present keyboard;

FIG. 6B is a side view of a first feature of the mechanism of FIG. 6A;

FIGS. 6C and 6D are a partial plan view and a partial perspective view,respectively, of a second feature of the mechanism of FIG. 6A;

FIGS. 7A and 7B are a partial schematic plan view and a partialschematic perspective view, respectively, of an alternative lockingmechanism for the keyboard;

FIG. 8 is a disassembled plan view of bases of the subframes;

FIG. 9 is a cross-sectional view of a further example of a keyboard inaccordance with the present invention;

FIG. 10 is an expanded view of a portion of FIG. 9; and

FIG. 11 is a diagrammatic perspective view of a further example of akeyboard in accordance with the present invention in its collapsedconfiguration with the addition of keys on the front panel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A keyboard 1 is particularly useful for providing a compact keyboard fora portable computer. The keyboard 1 is generally planar in the deployedconfiguration shown in FIG. 1. The keyboard 1 has plural keys 2distributed over its upper surface generally in a format which isfamiliar to users of computer keyboards in general. In particular, thereis a row 3 including function keys; a row 4 including digits (from 1 to9 and 0); three rows 5 which include alphabetic keys; and a space bar 6which, for reasons to be described below, is in two parts 6A,6B. Otherkeys such as “CTRL”, “ALT”, “TAB”, etc. which are familiar to computerkeyboard users are also provided generally in their conventionalpositions.

The keyboard 1 has a support frame 10 which is in four generallyrectangular portions referred to herein as subframes 11-14. Thesubframes 11-14 are connected in series at respective long edges to eachother by hinges 15 as shown. In particular, the first subframe 11 isconnected to the subframe 12 by hinges 15 at their adjacent corners,these hinges 15 being mounted on or towards the uppermost portion of thekeyboard 1. The third and fourth subframes 13,14 are similarly connectedat adjacent comers by hinges 15 on the uppermost surface of the keyboard1. The second and third subframes 12,13 are connected at their adjacentcorners by hinges 15 which are fixed on or towards the lowermost surfaceof the keyboard 1. Thus, as shown in FIGS. 3A and 3B for example, thekeyboard 1 folds in a concertina-like fashion through a W-shape in whichthe central axis 16 moves relatively upwards whilst the two outermostaxes 17 move relatively downwards. The arrangement of the keys 2 and thehinges 15 is preferably such as to allow the keyboard 1 to be completelycollapsed to the configuration shown in FIG. 3C in which the variouskeys 2 on the subframes 11-14 touch one another and depress such thatthe keys are stored under compression in the collapsed configuration.This provides for an extremely compact collapsed keyboard 1. Forexample, in the deployed configuration shown in FIG. 1, the keyboard mayhave a size of 30×15×0.5 cm with the keys protruding 3 mm above thiswhen not depressed, whereas, in the collapsed configuration, thecollapsed keyboard 1 may have a size of just 8×15×2 cm.

As the keyboard 1 is folded towards its collapsed configuration, thekeys immediately either side of the outermost folding axes 17 will tendto approach each other and, indeed, may obstruct the folding of thekeyboard 1. The keys may also overlap the outermost folding axes 17 inthe collapsed configuration, which may make the keys vulnerable todamage and also may produce an unsightly jagged edge in the collapsedconfiguration.

There are various possible ways of preventing these keys from hinderingcomplete collapse of the keyboard 1. For example, computer keys areoften bevelled so that their base is wider than their top. Thisbevelling alone may be sufficient to prevent the keys adjacent theoutermost axes 17 from contacting each other. Alternatively oradditionally, a dead space or recess may be formed under the keysadjacent the outermost axes 17, these recesses accommodating the edgesof these keys as the keyboard 1 is folded. The recesses may be coveredby a flexible flap which is moved aside by the keys when the keyboard 1is folded to its collapsed configuration. The recesses will be describedfurther below.

However, in the most preferred embodiment, the keys which otherwisemight cause obstruction are allowed to be slidable so that as thekeyboard 1 is folded, the slidable keys can move away from the axes 17to allow complete collapse of the keyboard 1 to take place. The use ofsliding keys means that the keyboard 1 can retain the familiarrelatively staggered layout of the keys in the deployed configuration,which is particularly important for touch typists who rely on thevarious keys 2 being in predetermined positions on a keyboard 1.Furthermore, the use of sliding keys allows those keys to be withdrawninto the folded keyboard 1, which provides a straight edge at theoutermost folding axes 17 and also allows the keys to be protected inthe collapsed keyboard 1.

The keys which are made slidable are preferably those that overlap orproject over the outermost axes 17. For convenience, the slidable keysmay be grouped in sets which respectively extend across the width of thesubframe 11-14 concerned. In particular, the first four digit keys 40mounted on the first subframe 11 are slidable away from the firstfoldable axis 17 (i.e. to the left in FIGS. 1A and 3A) and can move intoa recess 18 provided in edge of the subframe 11. Similarly, the lastthree digit keys 41 which are mounted on the fourth subframe 14 to theright hand side of the keyboard 1 can move into a recess 19 provided inthe edge of the subframe 14, the last set 41 of the digit keys 4 movingaway from the centre of the keyboard 1 and the rightmost folding axis17. In the first row of alphabetic keys 5 which is immediately below thedigit keys 4, the two sets 20,21 of central keys, i.e. those mounted onthe two central subframes 12,13, can move towards each other, i.e.towards the central axis 16 and away from the outermost axes 17, so thatthese sets of keys 20,21 clear the outermost axes 17 during folding ofthe keyboard 1. Other sets of keys supported on the central subframes12,13 and which also overlap the outermost axes 17 can be arranged toslide towards the central axis 16 as indicated in FIG. 3A, again toensure that these sets of keys do not obstruct folding of the keyboard1, such as sets 22,23. The last two rows of keys including the part 6Aof the space bar 6 on the second subframe 12 are movable as a set 23.Finally, if any of the keys overlap the central axis 16 by a significantdegree, for example the set 42 of digit keys supported by the thirdsubframe 13, such keys can be arranged to slide slightly away from thecentral axis 16 so that such keys 42 do not project beyond the edges ofthe respective subframes 11-14 when the keyboard 1 is in its collapsedconfiguration. It will be appreciated that the space bar 6 needs to besplit into two portions 6A,6B as mentioned above as the space bar 6crosses the central axis 16 and, as a consequence, will have two linkedelectrical connection contact points.

In FIG. 4, there is shown an exploded view of a typical subframe 11. Itwill be understood that the other subframes 12-14 are constructed in asimilar fashion. The subframe 11 has a planar rectangular base 50 madeof a rigid material such as metal or rigid plastics. A planar circuitboard 52 is fixed to the base 50 and is connected to circuit boards onthe other subframes 12,13,14 by a flexible wire loop (not shown). Arubber bubble sheet 54 fits over the circuit board 52 to provideelectrical connection to the circuit board 52 when a key 2 is pressed.The rubber bubble sheet 54 acts in a known manner and provides a springbias to the keys 2. A support structure 56 for the keys 2 fits over thebubble sheet 54 and is preferably fixed to the bubble sheet 54, forexample by gluing. The support structure 56 may be plastics and isdivided into individual cells 57 each of which supports a respective key2. The keys 2 are retained in their respective cells 57 by ascissor-action spring 58 fixed to the key 2 and respective cell 57. Thescissor-spring 58 acts in a known manner to secure and control themovement of the key 2. An upper edge trim 60 fits over the supportstructure 56 to provide rigidity and can be fixed to the base 50 by anysuitable means, such as by screws or clips (not shown). The hinges 15are fitted to the edge trim 60.

In a preferred embodiment, base 50 has recesses 51, the circuit board 52has recesses 53, and the bubble layer 54 has recesses 55, all of whichallow keys on an adjacent subframe to move into the recesses 51,53,55 asnecessary during folding as mentioned above. FIG. 8 shows the positionof the recesses 51 in the bases 50 of each of the subframes 11-14, thevarious recesses 51 being positioned according to the positions of thesliding keys mounted on the particular subframe 11-14. It will beappreciated that recesses are not required adjacent the central foldingaxis 16 for example because the central subframes 12,13 fold outwards.

In order to allow keys 40 to be slidable as mentioned above, thesections 54′,56′ of the bubble layer 54 and support structure 56 thatcorrespond to the sliding keys 40 are preferably made as separatecomponents, as indicated in FIG. 4 for example. As shown in FIGS. 5A to5C, the sliding portions 54′,56′ of the bubble layer 54 and supportstructure 56 have small rectangular slots 61 through which screws 62pass for fixing the sliding portions 54′,56′ to the base 50. Because thefixing screws 62 pass through rectangular slots 61, the sliding portions54′,56′ of the bubble layer 54 and support structure 56 can move duringfolding as necessary and therefore carry the sliding keys 40 with them.A similar construction is used for all of the sliding keys mentionedabove. Optionally, as shown in FIG. 5D, the screws 62 may be slightlylonger and pass through a small spring 63 before passing through thebubble layer 54 and support structure 56 to provide some freedom ofmovement in the vertical direction during folding of the keyboard 1.

A system of springs and flexible straps or links are preferably providedin order to encourage or ensure that the sliding keys move as requiredduring folding and unfolding of the keyboard 1. In particular, thosekeys 20,21,6A that move towards the central folding axis 16 areconnected to the adjacent keys towards which they move by flexiblestraps or links 70 which pass over the central folding axis 16 so that,as the keyboard 1 is folded, the sliding keys are pulled towards thecentral axis 16. Return springs 71 connect the other ends of thesesliding keys to fixed keys mounted on the outermost subframes 11,14 toensure that these sliding keys return to the proper position when thekeyboard 1 is unfolded to its deployed configuration. Optionally, thereturn springs 71 may be placed within the support structure 56 andconnected laterally to the screws 62.

The first set 40 of digit keys is preferably connected by a furtherspring 72 to the wall of the recess 18 in the first subframe 11, thespring 72 biasing the first set 40 of digit keys into the recess 18 whenthe keyboard 1 is folded. A resilient link 70 connects the other end ofthe first set 40 of digit keys to the adjacent fixed digit keys 43mounted on the second subframe 12, which ensures that the first set 40of digit keys are pulled back to their proper position when the keyboard1 is unfolded. A similar spring 73 connects the last set 41 of digitkeys mounted on the fourth subframe 14 to the recess 19 in order to biasthis last set 41 of digit keys into the recess 19 during folding. Thelast set of digit keys 41 is connected by a flexible link 74 to the setof digit keys 42 mounted on the third subframe 13 in order to carry thethird set 42 of digit keys away from the central folding axis duringfolding. A further spring 75 connects the other end of the third set 42of digit keys to the fixed digit keys 43 on the second subframe 12 sothat the third set 42 and last set 41 of digit keys are pulled back totheir proper position when the keyboard 1 is deployed.

A mechanism for locking the keyboard 1 in its deployed configuration isshown in FIGS. 6A to 6D. Three sprung bolts 80,81,82 slide in recesses83 provided in the edge trims 60 and/or bases 50 of the subframes 11-14.The bolts 80,81,82 are preferably connected in series to each other bywires 84. The wire 84 running through the first subframe 11 is connectedto a tab 85 which projects through an opening 86 in the edge trim 60 ofthe first subframe 11. The user simply pulls the tab 85 to the left asshown in the drawings, which causes the respective bolts 80,81,82 tomove to the left in the drawings, thereby allowing the keyboard 1 to befolded. The position of the tab 85 in the top left hand corner of thekeyboard 1 means that it will be locked in position by the secondsubframe 12 in the collapsed configuration of the keyboard 1. Springs 87bias the bolts 80,81,82 in the locking direction.

An alternative locking mechanism may have plural rigid rods or bars inplace of the wires 84 of the example shown in FIGS. 6A to 6D. The rodsare interconnected in series by flexible hinges such as of rubber and anend one of the rods is connected to the operating tab 85. The use ofrigid rods does away with the need for the springs 87 of the exampleshown in FIGS. 6A to 6D. The rods may further be connected to thevarious sets of sliding keys so that the keys are slid into position andthe keyboard 1 is locked open by movement of the tab 85 in a firstdirection. The tab 85 is operated in the reverse direction to withdrawthe locking rods and to slide back the sliding keys to allow thekeyboard 1 to be collapsed.

A yet further alternative locking mechanism is shown in FIGS. 7A and 7B.Instead of the linear bolts 80,81,82 of the example shown in FIGS. 6A to6D, sector-shaped locking bars 90,91,92 can pivot in sector-shapedrecesses 93 provided in the subframes 11-14. The locking bars 90,91,92are connected to one another by wires 94 which are again connected to atab 85 which projects from the surface of the first subframe 11. Whenthe tab 85 is pulled to the left, the respective locking elements90,91,92 are all caused to pivot out of locking engagement with theadjacent subframe 12,13,14, thereby allowing the keyboard 1 to befolded. The locking elements 90,91,92 are biased by springs 95 intoengagement with the adjacent subframe 12,13,14 so that the keyboard 1 islocked when in its deployed configuration.

The very outermost edges of the first and fourth subframes 11,14 arepreferably provided with upward facing curves 100,101 which allows thekeyboard 1 to have a smooth and attractive finish when in its collapsedor folded configuration. A clip 102 may be provided on one of the upwardcurves 100 so as to engage in a corresponding recess 102 on the otherupward curve 101 in order to lock the keyboard 1 in its collapsedconfiguration. A similar clip may act at the base of the second andthird subframes 12,13 to prevent the central portion of the keyboard 1from opening out when the keyboard 1 is in its collapsed configuration;such a clip may be provided by a thin magnetic strip attached to thebase 50 of the second and third subframes 12,13. The curves 100,101 alsoserve to protect any keys which overhang the central folding axis 16.This is facilitated by virtue of the first and fourth subframes 11,14being wider than the second and third subframes 12,13. It will beunderstood that various other locking mechanisms may be suitable forperforming the desired locking function and are within the scope of thepresent invention.

The relative height of the keys 2 can be such that the keys 2 touch eachother on their top surfaces when the keyboard 1 is in its foldedconfiguration, the keys 2 depressing each other so as to reduce thethickness of the folded keyboard 1 to an absolute minimum.

There is space within the subframes 11-14 to accommodate a short pieceof cable and connector for connecting the keyboard 1 to a device such asa computer. Alternatively or additionally, a small infra-red unit may becontained within the subframes 11-14 for providing a connection to asuitably equipped computer. As a further alternative, a connection cablecould be accommodated within the space under the curved sections100,101. Such a cable may have a slightly magnetic outer sheath so thatit can be stored tidily when the keyboard 1 is in its collapsedconfiguration.

An alternative mounting for the keys 2 is shown in FIGS. 9 and 10. Thebase 50 of each subframe 11-14 is provided with plural parallel rails110 of T-shape cross-section across its centre. Each rail 110 thereforeprovides opposed flanges 111 raised from the surface of the base 50.Corresponding side flanges 112 are provided at the edges of the base 50as shown. The support structure 56, particularly the sliding supportstructure 56′, to which the keys 2 are fixed is provided in each casewith a corresponding pair of opposed flanges 113 which engage under theflanges 111,112 of the base 50 to retain the support structure 56,56′ onthe base 50. This is a particularly advantageous method of mounting forthe sliding keys as manufacture of the keyboard 1 is simplified.

A further example of the present invention is shown in FIG. 11. Thefolding keyboard 1 is combined with a remote control unit having controlkeys 120 on an upper surface (i.e. the rear of one of the end subframes11) of the keyboard 1 when in its folded configuration. Thus, when thekeyboard 1 is in its folded configuration, it can be used as a remotecontrol device for controlling any suitable apparatus. The keyboard 1can be deployed for use as a keyboard whenever required, and can even beused to send signals corresponding to data input via the keyboard 1 tothe apparatus being controlled remotely. Examples of such includetelevisions, interactive television systems, screen telephones,computers connected to the Internet, so-called “network computers”(which have only a small storage capacity hard disk or no hard disk atall), etc. This combination of a remote control unit and a foldingkeyboard 1 according to the present invention conveniently provides theuser with full keyboard functions whilst allowing the remote controlunit to remain small and unobtrusive when keyboard functions are notrequired. This may be particularly advantageous in a domesticenvironment.

In a preferred embodiment keyboard 1 includes is constructed such thatat least some of the keys, and preferably at least some of the slidablekeys, are biased toward their deployed position when the keyboard isdeployed. Keys 2 can be biased by any suitable type of spring or thelike. It is further preferred that keyboard 1 be constructed such thatwhen it is in its collapsed configuration, the support structure encaseseach depressed key. This helps prevent damage to the keys duringtransport of the keyboard.

While an embodiment of the present invention has been described withparticular reference to the examples illustrated, it will be appreciatedthat variations and modifications may be made to the examples describedwithin the scope of the present invention. For example, the keys 2 maybe of the touch pad/membrane type instead of the mechanically sprungtype shown in the drawings. This may allow the keyboard 1 to have aslimmer cross-section in its collapsed configuration and may also savein manufacturing costs compared to the mechanically sprung keys 2described above. It may also avoid the need to have some of the keysslide during deployment and collapsing of the keyboard 1, which wouldcertainly provide savings in manufacturing costs. A particularly slimcollapsed keyboard 1 is very desirable when the keyboard 1 is combinedwith a remote control unit as described above, or with portable devicessuch as mobile telephones.

What is claimed is:
 1. A collapsible keyboard comprising: foursubstantially rigid subframes arrayed in a row, each pair of adjacentsubframes being relatively pivotably connected together along a foldingaxis, said folding axes being substantially mutually parallel; and aplurality of keys mounted on said subframes; the keyboard being foldableabout said folding axes between a deployed configuration in which thekeyboard is generally planar and a collapsed configuration.
 2. Thekeyboard according to claim 1, wherein the keyboard is foldable inopposite directions on adjacent folding axes.
 3. The keyboard accordingto claim 1, wherein at least some of said keys are slidable relative toa subframe in a direction transverse to said folding axes.
 4. Thekeyboard according to claim 3, further including at least one flexibleconnector connecting at least some of said slidable keys to other keysacross one of said folding axes such that said at least some of saidslidable keys slide relative to said subframe as the keyboard is foldedinto the collapsed configuration.
 5. The keyboard according to claim 3wherein at least some of said slidable keys are shifted into theirdeployed position when the keyboard is unfolded to the deployedconfiguration.
 6. The keyboard according to claim 1, further comprisinga support structure for said keys.
 7. The keyboard according to claim 6wherein said support structure comprises a matrix of cells, each cellaccommodating a respective key.
 8. The keyboard according to claim 7wherein at least some of said keys are depressed when the keyboard is inits collapsed configuration and said support structure encases eachdepressed key when the keyboard is in the collapsed configuration. 9.The keyboard according to claim 1, further comprising a supportstructure for said keys, wherein at least some of said keys are mountedso as to be slidable relative to a subframe in a direction transverse tosaid folding axes, and wherein portions of the support structure areslidable with said slidable keys.
 10. The keyboard according to claim 1,further comprising a lock for maintaining the keyboard in its deployedconfiguration.
 11. The keyboard according to claim 10 wherein said lockcomprises locking elements that are biased into recesses in saidsubframes in the keyboard.
 12. The keyboard according to claim 10wherein said lock includes a button and is releasable by operation ofsaid button.
 13. The keyboard according to claim 1, further comprising alock for locking the keyboard in its collapsed configuration.